It has become increasingly popular, particularly in the construction of commercial and industrial buildings and facilities to use prefabricated wall sections that are constructed off site and subsequently joined together at the building site. The panels are manufactured in a factory setting and can be either a standard shape or custom built. One source of such modular building systems is available from the Canam Manac Group of Canada under the trademark of MUROX.TM..
The panels are typically formed from a frame work of structural steel members. A generally rectangular outlined shape is typically produced. The outer edges of the panel usually comprise the main structural members that provide the panels with rigidity. For example, a pair of vertical members are often used on each upright edge of the panel. The vertical members are typically formed as channel-shaped beams in which the bottom leg of the channel comprises the outer edge of the panel while the upright legs of the channel extend inwardly toward the center of the panel. At least two horizontal cross members are provided at the top and bottom edges of the panel. The cross members extend horizontally between the two channel-shaped vertical members and are usually joined to the channel-shaped vertical members by welding, bolting, riveting or another acceptable joining technique. The interior of the panel can be filled with a variety of insulation materials and other fillings. Utilities can be prearranged inside the panel. Each side of the panel can be provided with an appropriate skin covering. Panels are brought to a building site and assembled together using bolts that typically join two of the channel-shaped upright members together so that the panels are arranged side by side to form a completed wall. In general the vertical U-shaped members are joined using bolts that pass through holes in each of the members. The holes can be predrilled in each panel before assembly, or can be drilled on site after the panels have been aligned with each other. Bolts are used to lock the panels together at the construction site.
Since horizontal members are prone to expand and contract due to thermal expansion, it is desirable to include expansion joints between panels. A variety of techniques have been used to create expansion joints. Typically, packing or other spacers can be prearranged between specific panels to allow groups of panels to expand and contract. In a standard size building expansion can account for an inch or more of horizontal movement over the length of a wall. A disadvantage to providing expansion joints is that it often slows down the construction process and can induce inaccuracies and misalignments in the joining of building panels. For this reason, joints are often established only where specifically needed along the length of the wall.
It is therefore an object of this invention to provide a method and apparatus for quickly and reliably accounting for expansion and contraction in assembled modular building panels.